Today's thriving economy is predicated in part upon a manufacturer's ability to deliver its products to the end users. To achieve this goal, often manufacturers ship large quantities of packaged products to wholesalers and distributors which, in turn, ship smaller quantities of packaged products to retailers and dealers. To commence the shipping process, the packaged products are stored in a manufacturer's warehouse and are loaded onto pallets and moved into trailer trucks.
Conventional pallets have long been the workhorses of the shipping industry. These pallets are fabricated from a variety of materials and, for many decades, have effectively moved large quantities of products from one location to another. Wood is a common material used to construct pallets. Unfortunately, depending upon the use and abuse that the pallet undergoes when shipping products, the wooden pallet typically has a limited useful life, sometimes as short as a single haul. Even worse, a careless lift operator can break a pallet even before its first haul. Furthermore, over the past few years, the cost of wood has become rather expensive thereby causing the transportation industry to seek alternative, less-costly materials for fabricating pallets. Various types of plastics as well as metal have been used to fabricate pallets. Although both of these materials have been viable for use, these pallets also yield a limited useful life due to the use and abuse that the pallets undergo during the shipping process.
Additionally, wooden, plastic and metal pallets are bulky. When not in use, these pallets occupy substantial storage space. Also, it is necessary that a shipping warehouse maintain a large number of these pallets in stock at all times. Otherwise, shipments of products cannot be made. In some instances, pallets must be returned to the shipping warehouse in order to maintain the appropriate number in stock.
Due to cost, breakage, storage, inventory and limited useful life of conventional pallets, the transportation industry responded to these concerns by the introduction of a pull sheet pallet. In general, a pull sheet pallet is a sheet of material such as polypropylene and high density polyethylene. Both of the materials have a high tensile strength. The pull sheet pallet is placed upon a floor of a warehouse or truck so that cargo can be loaded on it. The pull sheet pallet has a lip which projects outwardly and upwardly in order that a gripper bar of a motorized lift vehicle can grasp the lip of the pull sheet and pull the pull sheet pallet onto a platen of the lift vehicle. A segment of the transportation industry considers the pull sheet pallet to be a low cost and effective substitute for conventional pallets for several reasons. First, pull sheets are inexpensive. In fact, the industry considers them to be discardable for recycling after its first use. Second, pull sheet pallets are millimeters thick as opposed to conventional pallets which are inches thick. Thus, pull sheet pallets are lightweight and compact for storage. Third, although pull sheet pallets occasionally tear when being pulled, pull sheet pallets are far more durable than conventional pallets.
One type of a pull sheet pallet is disclosed in U.S. Pat. No. 5,226,372 to Frenkel et al. This pull sheet pallet has a plurality of nibs projecting from a lower surface thereof and a plurality of corresponding recesses formed into an upper surface thereof. The pull sheet pallet is fabricated of a plastic material such as polypropylene and high density polyethylene having a thickness of between 0.040 inches and 0.125 inches. This plastic material is stiff yet resilient so that when cargo is placed on the upper surface of the pallet and thereafter transported, shock which is continually being induced can be absorbed by minute contractions and subsequent expansions of the nibs. The pull sheet pallet also includes a lip which can be grasped by the griper bar of the motorized lift vehicle so that the loaded pull sheet pallet can be pulled onto the platen or held for sliding the platen thereunder. Further, the nibs support the load of the cargo above a support surface in a manner whereby only apex portions of the nibs contact the support surface. This feature not only allows contraction and expansion of the nibs but also reduces the amount of force necessary to overcome friction when the pull sheet pallet pulled onto and pushed off of the platen.
However, there is a drawback associated with employing prior art pull sheet pallets such as the one disclosed in the above-cited patent. Pull sheet pallets are fabricated from various types of plastic sheet material which generally have smooth surfaces. Since a smooth upper surface contacts the cargo when loaded thereon, the cargo tends to slide off of the pull sheet pallet when acted on by a force.
In an effort to resolve this problem with cargo sliding off of the pull sheet pallet, one manufacturer has fabricated a laminated pull sheet whereby a second sheet of plastic having a higher coefficient of surface friction is laminated as an upper sheet onto the base sheet. The cargo is loaded onto the upper sheet. Although effective in reducing the amount of sliding that the cargo undergoes when acted upon by a force, the lamination contributes to increased material costs as well as increased manufacturing costs.
There is a need in the transportation industry to provide a low-cost pull sheet pallet which inhibits cargo from sliding when acted on by a force. There is also a need in the industry to provide a low-cost pull sheet that can either be discarded after the first use or reused depending on the desires of the shipper. It would be beneficial if the pull sheet pallet had a single ply construction and was simple to manufacture. The present invention addresses these needs and provides these benefits.